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- binocular stereo vision sensor
- large field of view calibration
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- laser tracker
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A High-Throughput Drug Screening Strategy for Detecting Rhodopsin P23H Mutant Rescue and Degradation
摘要： Inherent instability of the P23H mutant opsin accounts for approximately 10% of autosomal dominant retinitis pigmentosa cases. Our purpose was to develop an overall set of reliable screening strategies to assess if either stabilization or enhanced degradation of mutant rhodopsin could rescue rod photoreceptors expressing this mutant protein. These strategies promise to reveal active compounds and clarify molecular mechanisms of biologically important processes, such as inhibition of target degradation or enhanced target folding. METHODS. Cell-based bioluminescence reporter assays were developed and validated for high-throughput screening (HTS) of compounds that promote either stabilization or degradation of P23H mutant opsin. Such assays were further complemented by immunoblotting and image-based analyses. RESULTS. Two stabilization assays of P23H mutant opsin were developed and validated, one based on b-galactosidase complementarity and a second assay involving bioluminescence resonance energy transfer (BRET) technology. Moreover, two additional assays evaluating mutant protein degradation also were employed, one based on the disappearance of luminescence and another employing the ALPHA immunoassay. Imaging of cells revealed the cellular localization of mutant rhodopsin, whereas immunoblots identi?ed changes in the aggregation and glycosylation of P23H mutant opsin. CONCLUSIONS. Our ?ndings indicate that these initial HTS and following assays can identify active therapeutic compounds, even for dif?cult targets such as mutant rhodopsin. The assays are readily scalable and their function has been proven with model compounds. High-throughput screening, supported by automated imaging and classic immunoassays, can further characterize multiple steps and pathways in the biosynthesis and degradation of this essential visual system protein.
关键词： ocular pharmacology,retinal degeneration,GPCR,phototransduction,rod photoreceptors,rhodopsin,misfolded protein
更新于2025-11-21 11:20:48
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Matching the LenStar optical biometer to A-Scan ultrasonography for use in small animal eyes with application to tree shrews
摘要： We describe an analysis strategy to obtain ultrasonography-matched axial dimensions of small animal eyes using the LenStar biometer. The LenStar optical low-coherence reflectometer is an attractive device for animal research due to its high precision, non-invasiveness, and the ability to measure the axial dimensions of cornea, anterior chamber, lens, vitreous chamber, and axial length. However, this optical biometer was designed for clinical applications in human eyes and its internal analysis provides inaccurate values when used on small eyes due to species-dependent differences in refractive indices and relative axial dimensions. The LenStar uses a near infrared light source to measure optical path lengths (OPLs) that are converted by the LenStar’s EyeSuite software into geometrical lengths (GLs) based on the refractive indices and axial dimensions of the human eye. We present a strategy that extracts the OPLs, determines refractive indices specific for the small animal eye of interest and then calculates corrected GLs. The refractive indices are obtained by matching the converted LenStar values to ultrasonography values in the same eyes. Using LenStar and ultrasonography measures of tree shrew eyes, we found that, compared to ultrasonography, the internal calculations of the LenStar underestimate the axial dimensions of all ocular compartments of the tree shrew eye: anterior segment depth by 6.17 ± 4.50%, lens thickness by 1.37 ± 3.06%, vitreous chamber depth by 29.23 ± 2.35%, and axial length by 10.62 ± 1.75%. Using tree-shrew specific refractive indices, the ocular compartment values closely matched the ultrasonography measures. Our analysis strategy can be easily translated to other species by obtaining a similar paired data set using ultrasonography and LenStar, and applying our step by step procedures.
关键词： LenStar,Ultrasonography,Tree Shrews,Ocular Axial Dimensions,Refractive Indices
更新于2025-09-23 15:23:52
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Research progress about the effect and prevention of blue light on eyes
摘要： ● In recent years, people have become increasingly attentive to light pollution influences on their eyes. In the visible spectrum, short-wave blue light with wavelength between 415 nm and 455 nm is closely related to eye light damage. This high energy blue light passes through the cornea and lens to the retina causing diseases such as dry eye, cataract, age-related macular degeneration, even stimulating the brain, inhibiting melatonin secretion, and enhancing adrenocortical hormone production, which will destroy the hormonal balance and directly affect sleep quality. Therefore, the effect of Blu-rays on ocular is becoming an important concern for the future. We describe blue light’s effects on eye tissues, summarize the research on eye injury and its physical prevention and medical treatment.
关键词： ocular injury,prevention,blue light
更新于2025-09-23 15:23:52
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Noninvasive biodegradable nanoparticles-in-nanofibers single-dose ocular insert: <i>in vitro</i> , <i>ex vivo</i> and <i>in vivo</i> evaluation
摘要： Aim: This study involves, for the first time, the development of mucoadhesive biodegradable polymeric-multilayered nanoparticles-in-nanofibers (NPs-in-NFs) matrix as an innovative single-dose noninvasive ocular-insert that could substitute conventional ocular dosage-forms. Materials & methods: Azithromycin-loaded poly(lactic-co-glycolic acid) copolymer/pluronic NPs were developed then incorporated into electrospun polyvinylpyrrolidone NFs, and tested for their efficient treatment of ocular bacterial infection. Results: Release and permeation studies proved the ability of the insert to control drug release over 10 days. Conclusion: The incorporation of NPs into NFs achieved several other benefits like increasing ocular residence and contact time with conjunctival tissue, accurate dose delivery, sustaining drug release with constant rate, reducing frequency of administration, improving bioavailability along with decreasing incidence of visual and systemic side effects.
关键词： nanofibers,electrospun,bacterial infection,single-dose,ocular,azithromycin
更新于2025-09-23 15:23:52
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Portable Autorefractors for Detecting Axial Length Changes in Space
摘要： We evaluated the reproducibility of two portable, self-administered autorefractors (Netra and SVOne Pro) to assess the time course of visual changes on the ISS. METHODS: We measured cycloplegic refractive error at 5 visits at least a week apart in 13 subjects (6 women, 7 men, 30 6 9 yr) using both devices seated and also prone with lower body positive pressure (LBPP) applied. Axial length was measured with an optical biometer. Subjects completed a questionnaire on device preferences. RESULTS: The SVOne seated intrasession reproducibility coefficient (RPC) was 0.37 diopters (D), while the Netra's was 0.41 D. Intersession seated results were: RPC 5 0.67 D for the SVOne and RPC 5 0.54 D for the Netra. The average seated to prone LBPP differences were significantly different from zero for both the SVOne and Netra. The SVOne was preferred in four out of five categories on the questionnaire and took half the time to complete a measurement set compared to the Netra. DISCUSSION: Users preferred the SVOne and it took less time. An SVOne refraction change of 0.67 D from baseline would happen by chance less than 5% of the time. If multiple separate measurements were taken, the detection limit could be reduced (e.g., three repeated measurements could reduce it to 0.38 D). Since astronauts with visual changes show spherical equivalent changes of 0.5 to 1.0 D, in-flight autorefractors could help determine the time course of refractive changes in space from which changes in axial length could be inferred.
关键词： spaceflight-associated neuro-ocular syndrome,portable autorefractor,axial length,refractive error
更新于2025-09-23 15:23:52
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Biometry in cataract surgery
摘要： Purpose of review To review the literature in 2017 and 2018 pertaining to biometry for cataract surgery and report pertinent findings. Recent findings New devices using swept-source ocular coherence tomography can measure axial length in dense cataracts more frequently than common biometers. Computer-assisted registration may be superior to intraoperative aberrometry for toric intraocular lens (IOL) placement. Soft contact lenses may not require removal as long before biometry as previously thought. The Barrett Universal II IOL formula has been found to perform well at all axial lengths. Summary New swept-source ocular coherence tomography biometers are more frequently successful at measuring axial length in dense cataracts which promises to improve refractive outcomes. Accuracy in toric IOL placement is likely to increase with improved devices. It may not be necessary to have patients remove soft contact lens any more than 2 days prior to biometry. The Barrett Universal II IOL formula may be used confidently for most eyes. Advancements acknowledged, purchasing new equipment will not be necessary for all surgeons.
关键词： swept-source ocular coherence tomography,toric,cataract,biometry
更新于2025-09-23 15:23:52
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Contact Lenses || Optics and Lens Design
摘要： Some aspects of contact lens design and optics are rarely applied nowadays, as they are less relevant to modern practice, but readers may still need to refer to them. They are available at: https://expertconsult.inkling.com/, whereas the more relevant topics are included here. The appendix, available at: https://expertconsult.inkling.com/, also describes various equations that are used in contact lens work, while the online resources include programs relating to both the optics and to lens design. There are two main aspects to be considered when dealing with the optics of contact lenses: the effects on the wearer of the optical differences from spectacles and the necessity for the practitioner to understand the components which affect the back vertex power (BVP) of the contact-lens/liquid*-lens system. There is some overlap of these two aspects, but for the sake of convenience they are discussed separately in the first two sections of the chapter. In the second section a set of approximate rules is included, the use of which should permit practitioners to make quick and reasonably accurate estimates of changes in power caused by altering certain lens parameters. The Cartesian sign convention2 is used throughout. For further understanding of the basic principles involved, readers are referred to the works of Bennett (1985), Tunnacliffe (1993), Freeman and Hull (2003), Douthwaite (2006) and Rabbetts (2007).
关键词： Lens Design,Astigmatism,Optics,Bifocal Contact Lenses,Power Variations,Contact Lenses,Ocular Refraction,Aberrations,Spectacles
更新于2025-09-23 15:23:52
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The Relationship Between High-Order Aberration and Anterior Ocular Biometry During Accommodation in Young Healthy Adults
摘要： PURPOSE. This study investigated the anterior ocular anatomic origin of high-order aberration (HOA) components using optical coherence tomography and a Shack-Hartmann wavefront sensor. METHODS. A customized system was built to simultaneously capture images of ocular wavefront aberrations and anterior ocular biometry. Relaxed, 2-diopter (D) and 4-D accommodative states were repeatedly measured in 30 young subjects. Custom software was used to correct optical distortions and measure biometric parameters from the images. RESULTS. The anterior ocular biometry changed during 2-D accommodation, in which central lens thickness, ciliary muscle thicknesses at 1 mm posterior to the scleral spur (CMT1), and the maximum value of ciliary muscle thickness increased significantly, whereas anterior chamber depth, CMT3, radius of anterior lens surface curvature (RAL), and radius of posterior lens surface curvature (RPL) decreased significantly. The changes in the anterior ocular parameters during 4-D accommodation were similar to those for the 2-D accommodation. Z0 4 decreased significantly during 2-D accommodation, and Z(cid:2)1 6 shifted to negative values during 4-D accommodation. The change in Z0 4 negatively correlated with those in CMT1, and the negative change in Z1 3 correlated with changes in RAL and CMT1. CONCLUSIONS. HOA components altered during step-controlled accommodative stimuli. Ciliary muscle first contracted during stepwise accommodation, which may directly contribute to the reduction of spherical aberration (SA). The lens morphology was then altered, and the change in anterior lens surface curvature was related to the variation of coma.
关键词： anterior ocular biometry,ciliary muscle,wavefront aberration,optical coherence tomography
更新于2025-09-23 15:22:29
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Comparative Study of Optical Coherence Tomography Angiography and Phase-Resolved Doppler Optical Coherence Tomography for Measurement of Retinal Blood Vessels Caliber
摘要： Purpose: To compare the accuracy of Doppler optical coherence tomography (DOCT) and OCT angiography (OCTA) for measuring retinal blood vessel caliber at different flow rates. Methods: A research-grade 1060-nm OCT system with 3.5-lm axial resolution in retinal tissue and 92,000 A scan/s image acquisition rate was used in this study. DOCT and OCTA measurements were acquired both from a flow phantom and in vivo from retinal blood vessels in six male Brown Norway rats. The total retinal blood flow (TRBF) was modified from baseline to 70% and 20% of baseline by reducing the ocular perfusion pressure (OPP). The retinal blood vessel caliber (RBVC) was measured from OCTA and DOCT images. The caliber measurements were conducted by two separate graders using a custom MATLAB-based image processing algorithm. Results: The RBVC measured with OCTA and DOCT for normal blood flow rates were not significantly different (56.69 6 12.17 and 57.17 6 9.46 lm, P ? 0.27, respectively). However, significant differences were detected when TRBF was reduced to 70% (55.69 6 11.56 vs. 50.62 6 8.85 lm, P , 0.01) and 20% (50.29 6 9.29 vs. 44.88 6 7.13 lm, P , 0.01) of baseline. Conclusions: Reduced TRBF resulted in inaccuracy of the RBVC measurements with DOCT in both the phantom and animal study. This result suggests that OCTA is a more accurate tool for RBVC evaluation when applied to retinal diseases associated with reduced TRBF, such as glaucoma and diabetic retinopathy. Translational Relevance: Results from this study are directly applicable to clinical studies of retinal blood flow measured with OCTA and DOCT.
关键词： optical coherence tomography angiography,ocular perfusion pressure,retinal imaging,doppler optical coherence tomography
更新于2025-09-23 15:22:29
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Ocular Spot Fluorometer Equipped With a Lock-In Amplifier for Measurement of Aqueous Flare
摘要： Purpose: To evaluate a custom-made ocular fluorometer for detection of intensity of light scatter (ILS) from the anterior chamber (A/C) as an objective measure of aqueous flare. Methods: The fluorometer, equipped with a lock-in amplifier, was employed in the scatter mode to detect ILS from A/C. Measurements were performed with two illumination slit widths of 0.5 and 0.25 mm. The axial resolution at these slit widths were 80 and 200 lm, respectively. Healthy and pseudophakic eyes, with grade 0 Standardization of Uveitis Nomenclature (SUN) score, were employed as control subjects. ILS was also recorded in a cohort of patients who had undergone phacoemulsification and showed grades 1t or 2t on postoperative days 1 and 4. Results: The inter- and intraobserver variabilities in the measurement of ILS were not significant. In cataract patients, ILS was significantly higher on postoperative day 1 relative to healthy eyes. By day 4, ILS decreased significantly and was only marginally different from ILS in quiet pseudophakic eyes or healthy eyes. Eyes with higher SUN scores showed proportionately increased ILS. The receiver-operator characteristic analysis indicated no advantage in using the smaller slit width in discriminating ILS at different SUN scores although it provided higher axial resolution. Conclusions: The lock-in–based spot fluorometer is reliable for measurement of ILS with high precision and accuracy. The measured ILS correlates linearly with SUN scores and can be used to provide a higher granularity for recording aqueous flare.
关键词： ocular fluorometer,lock-in amplifier,SUN grading,light scatter,blood–aqueous barrier,aqueous flare,uveitis
更新于2025-09-23 15:22:29